The present invention relates to a case wherein a magnetic tape cassette, such as a digital video cassette (DVC), is stored and specifically relates to a structure for the prevention of incorrect insertions which are liable to occur at the time to store a magnetic tape cassette.
There have been proposed various types of magnetic tape cassette storage cases (hereinafter referred to simply as a storage case) so as to match the modes of the magnetic tape cassettes to be stored therein. An example of a conventional storage case and that of a magnetic tape cassette are described now with references to FIGS. 1 and 2.
As shown in FIG. 1, a storage case 41 comprises a storage part 43 for storing a magnetic tape cassette 81 that is shown in FIG. 2, a lid part 45 and a hinge part 47. The storage part 43 comprises a flat plate part 51, a lateral wall part 53 which is integrally formed at an outer circumferential part thereof, and reel lock ribs 55a and 55b which are formed at a part comparatively close to a rear end of the flat plate part 51. If stored appropriately, the magnetic tape cassette 81 that is shown in FIG. 2 is fitted inside the lateral wall part 53 as indicated by imaginary lines in FIG. 1.
The lid part 45 comprises a flat plate part 61 and a lateral wall part 63 which is integrally formed on three sides of the outer circumferential part thereof. The hinge part 47 comprises thin grooves 73a and 73b formed on both sides of a plate part 71 and these grooves 73a and 73b function to close the storage part 43 and the lid part 45 like a book.
A flange 51a which is formed of the flat plate part 51 protruding outward is provided on the outside of the lateral wall part 53 which constitutes the storage part 43. When the storage part 43 is closed by the lid part 45, the outer sides of the lateral wall part 53 of the storage part 43 are covered by the lateral wall part 63 of the lid part 45 and, since the storage part 43 is prevented from plunging into the lid part 45 with provision of the flange part 51a, the entire case can retain a certain thickness.
On an inner surface of the lateral wall part 63, a lock part 53a is formed as a recess in an outer surface of the lateral wall part 53 and a locking projection 63a is formed at a position which corresponds to the lock part 53a when the storage part 43 is closed by the lid part 45. When the storage part 43 is fully closed by the lid part 45, the lock part 53a is locked by the locking projection 63a to prevent the storage part 43 and the lid part 45 from being opened unexpectedly.
The magnetic tape cassette 81 is now described with references to FIG. 2. FIG. 2 is a perspective view of the magnetic tape cassette 81 from the bottom side thereof, wherein the upper half case 83 is shown on the lower side while the lower half case 85 is shown on the upper side. Two round openings 87a and 87b are formed in the lower half case 85 with exposure of engagement parts 89a and 89b that are integral parts of reel hubs which a magnetic tape is wound around (these are not shown in the figure).
The functions imparted to the engagement parts 89a and 89b are to feed out and wind up the magnetic tape while mounted on a VTR and to lock the magnetic tape cassette 81 onto the reel lock ribs 55a and 55b for prevention of loose movement thereof while stored in the storage case 41.
An outer lid 91 is provided on the front side of the magnetic tape cassette 81 so as to be rotated freely and, if mounted on the VTR or such, the magnetic tape is pulled out after the outer lid 91 has been rotated in a direction indicated by an arrow A in FIG. 2. A recession of a front opening 93 is formed approximately at the inside center of the outer lid 91 as if by incising the upper and lower half cases 83 and 85 and, on an edge of the front opening 93, a stepped part 95 is formed. These respectively function as predetermined when the magnetic tape cassette 81 is mounted on the VTR.
When the magnetic tape cassette 81 is stored in the storage case 41, the magnetic tape cassette 81 is fitted inside the lateral wall part 53 as indicated by imaginary lines in FIG. 1 and pushed in while the reel lock ribs 55a and 55b are inserted into round engagement holes B which are formed at the centers of the engagement parts 89a and 89b. Being moderately elastic, the reel lock ribs 55a and 55b are lightly pressure-inserted into the engagement holes B and thus the magnetic tape cassette 81 is stored inside the storage case 41.
The structure of the storage case 41, however, has such a problem as below at the time to store the magnetic tape cassette 81. That is, even if the magnetic tape cassette 81 is placed with the rear side front, the magnetic tape cassette can be supported between the lateral walls 53 and, since the reel lock ribs 55a and 55b are moderately elastic, the lid part 45 can be closed to some extent when the lid part 45 is pressed strongly. In this case, it may happen that the magnetic tape cassette 81 is deformed by pressure at inappropriate positions in contact with the reel lock ribs 55a and 55b.